Interpretation of the Jurassic Entrada sandstone play using 3D seismic attribute analysis, Uinta Basin, Utah

2006 ◽  
2021 ◽  
pp. 1-17
Author(s):  
Karen M. Leopoldino Oliveira ◽  
Heather Bedle ◽  
Karelia La Marca Molina

We analyzed a 1991 3D seismic data located offshore Florida and applied seismic attribute analysis to identify geological structures. Initially, the seismic data appears to have a high signal-to-noise-ratio, being of an older vintage of quality, and appears to reveal variable amplitude subparallel horizons. Additional geophysical analysis, including seismic attribute analysis, reveals that the data has excessive denoising, and that the continuous features are actually a network of polygonal faults. The polygonal faults were identified in two tiers using variance, curvature, dip magnitude, and dip azimuth seismic attributes. Inline and crossline sections show continuous reflectors with a noisy appearance, where the polygonal faults are suppressed. In the variance time slices, the polygonal fault system forms a complex network that is not clearly imaged in the seismic amplitude data. The patterns of polygonal fault systems in this legacy dataset are compared to more recently acquired 3D seismic data from Australia and New Zealand. It is relevant to emphasize the importance of seismic attribute analysis to improve accuracy of interpretations, and also to not dismiss older seismic data that has low accurate imaging, as the variable amplitude subparallel horizons might have a geologic origin.


1995 ◽  
Vol 35 (1) ◽  
pp. 65
Author(s):  
S.I. Mackie ◽  
C.M. Gumley

The Dirkala Field is located in the southern Murta Block of PEL's 5 and 6 in the southern Cooper and Eromanga Basins. Excellent oil produc­tion from a single reservoir sandstone in the Juras­sic Birkhead Formation in Dirkala-1 had indicated a potentially larger resource than could be mapped volumetrically. The hypothesis that the resource was stratigraphically trapped led to the need to define the fluvial sand reservoir seismically and thereby prepare for future development.A small (16 km2) 3D seismic survey was acquired over the area in December 1992. The project was designed not only to evaluate the limits of the Birkhead sand but also to evaluate the cost effi­ciency of recording such small 3D surveys in the basin.Interpretation of the data set integrated with seismic modelling and seismic attribute analysis delineated a thin Birkhead fluvial channel sand reservoir. Geological pay mapping matched volu­metric estimates from production performance data. Structural mapping showed Dirkala-1 to be opti­mally placed and that no further development drill­ing was justifiable.Seismic characteristics comparable with those of the Dirkala-1 Birkhead reservoir were noted in another area of the survey beyond field limits. This led to the proposal to drill an exploration well, Dirkala South-1, which discovered a new oil pool in the Birkhead Formation. A post-well audit of the pre-drill modelling confirmed that the seismic response could be used to determine the presence of the Birkhead channel sand reservoir.The acquisition of the Dirkala-3D seismic survey demonstrated the feasibility of conducting small 3D seismic surveys to identify subtle stratigraphically trapped Eromanga Basin accumulations at lower cost and risk than appraisal/development drilling based on 2D seismic data.


2016 ◽  
Author(s):  
Chen Maoshan ◽  
Hao Yanguo ◽  
Dai Lihua ◽  
Li Hong ◽  
Wang Fei

2019 ◽  
Vol 7 (1) ◽  
pp. T49-T66
Author(s):  
Osareni C. Ogiesoba ◽  
William A. Ambrose ◽  
Robert G. Loucks

We have conducted seismic-attribute analysis at the Serbin field — in an area straddling Lee, Fayette, and Bastrop Counties and covering approximately [Formula: see text] (approximately [Formula: see text]) — using new, reprocessed, 3D seismic data to provide additional understanding of depositional environments and better predict the distribution of hydrocarbon sweet spots. We converted the 3D seismic volume into a log-lithology volume and integrated core data to examine the distribution of lithology and interpret depositional environments. By conducting multiattribute analysis, we predicted resistivity (deep-induction log) volume and generated a resistivity map to identify hydrocarbon sweet spots. Our results show that reservoir sandstones in the Serbin field are storm-dominated, shelf-sand deposits. Although individual sandstone beds are lenticular and discontinuous, they collectively constitute a sheet-like geometry, trending northeast to southwest. On the basis of resistivity maps and rock property versus seismic-amplitude crossplots, we differentiated reservoirs in the lower Taylor Formation into two zones: (1) a northwest, high-resistivity, high-acoustic impedance zone and (2) a southeast, low-resistivity, low-acoustic impedance zone. The results also indicated that hydrocarbon sweet spots in the Serbin field are characterized by high resistivity and high impedance. Furthermore, the log-lithology method, although fast and effective, is limited because it cannot take into account sandstone zones having low acoustic impedance.


Geophysics ◽  
2015 ◽  
Vol 80 (2) ◽  
pp. B35-B43 ◽  
Author(s):  
Zhiguo Wang ◽  
Jinghuai Gao ◽  
Daxing Wang ◽  
Qiansheng Wei

The Lower Permian Xiashihezi Formation of the Ordos Basin is the largest producer of tight gas sand in China. The controls on tight gas production are many and include a variety of geologic, hydrodynamic, and engineering factors from one well to another throughout the basin. In this study, we considered data from a [Formula: see text] 3D seismic volume and logs from 17 wells to investigate the geologic controls on gas production in the [Formula: see text] member of the Xiashihezi Formation, eastern Sulige gas field, Ordos Basin. Our objective was to determine the potential of applying multiple seismic attributes to identify the higher productivity areas of a tight gas sand reservoir. To achieve this, we used amplitude, complex traces, spectral decomposition, and seismic attenuation attributes derived from the 3D seismic volume to detect gas-bearing sand areas. The results of seismic attribute analysis revealed that no single attribute is correlated to higher productivity areas. The qualitative correlations between attributes and production records reflected that higher productivity areas are associated with seismically definable higher amplitude, more stable phase, tuning frequency, and stronger attenuation features in the study area. Meanwhile, three outlier wells in the seismic attribute analysis provided a reminder of the uncertainty in geologic interpretation. The gas-sand reservoir evaluation results suggested that the Pareto principle helps to enhance the interpretation needed to determine the productivity distribution of [Formula: see text] tight-gas reservoir in the study area.


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